Multi-output valve useful to promote non-stationary flame

ABSTRACT

A valve useful in distributing gas received in one inlet to several outlets in a sequence, and burner apparatus including this valve for feeding material in sequence to outlets of a burner thereby forming a non-stationary flame at the burner.

This application claims priority to U.S. Provisional Application Ser.No. 60/900,147, filed Feb. 8, 2007, the content of which is herebyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to apparatus and methods useful incarrying out combustion.

BACKGROUND OF THE INVENTION

Many industrial processes require subjecting material to elevatedtemperatures on the order of 1000° F. to 3000° F. Examples of suchprocesses include melting aluminum and other metals, maintaining moltenmetal in the molten state, melting glassmaking materials, andmaintaining glass in the molten state. To generate the required elevatedtemperature, processes requiring such elevated temperatures oftencombust carbonaceous fuel, in one or more burners each of which producesa flame situated close enough to the material that the heat ofcombustion establishes the desired elevated temperature in the material.

Typically the one or more burners used for this purpose each generate aflame that extends outward from the burner in a fixed position, such asextending from a side wall of a furnace across and over the top of aportion of the material to be heated. Such arrangements are notnecessarily as efficient as possible, because the temperatures atvarious points around the outer surface of the flame and along thelength of the flame are not uniform so that there is a region of theflame that has the highest temperature and heat flux to the material.This lack of uniformity means that the position of the burner relativeto the material being heated, and the conditions under which the burneris operated, must be set so that the highest temperatures and heat fluxgenerated by the burner are not so high as to produce unwanted resultssuch as “hot spots” in the material or the enclosure in which thecombustion is being carried out, excessive oxidation of the material, ordamage to the enclosure. However, doing so often requires acceptingtemperatures at other points around the flame that are not as high ascould be tolerated, and thereby requires accepting less than optimumperformance of the burner.

This lack of efficiency has heretofore been considered acceptable for anumber of reasons including the absence of a useful method and apparatusthat can provide greater uniformity of temperature. The presentinvention provides apparatus and methods of use that overcome this lackof efficiency.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a method and apparatus that are useful inpermitting combustion to be carried out in a manner that affords a moreuniform temperature of the surface of the material to be heated, orheated and melted.

One aspect of the present invention comprises a valve useful for feedinggas to one or more than one outlets at a total flow rate that iscontrolled independently of the number of such outlets, comprising

-   -   a valve body having a valve chamber therein having opposed first        and second ends and a side surface extending between said ends,        the valve chamber including a first region that extends from the        first end of the valve chamber and that has an axis,    -   a valve distributor within the valve chamber and rotatable        therein in said first region about said axis, the valve        distributor having opposed first and second ends and a side        surface between said ends, that is positioned with its first end        facing the first end of the valve chamber and with its side        surface facing at least a portion of the first region of the        valve chamber,    -   said valve chamber including an open space that is bounded by        the second end of said valve distributor, the second end of the        valve chamber, and the side surface of said valve chamber,    -   the valve body having an inlet extending therethrough from the        outer surface of said valve body to said open space,    -   the valve distributor containing a channel extending inwardly        from the side surface of the valve distributor and extending        from the second end of the valve distributor axis at least a        portion of the distance toward the first end of the valve        distributor, to receive gas from said open space,    -   the valve body having two or more outlets extending therethrough        from the outer surface of said valve body to points in the first        region of the valve chamber that face the side surface of the        valve distributor or at least a portion of said channel,    -   wherein the outlets are dimensioned and located with respect to        each other so that at any rotational orientation of the valve        distributor the channel is open to one outlet or to more than        one outlet, and so that when the channel is open to more than        one outlet at the same time the sum of the interfacial areas at        said outlets stays within 90%, preferably within 50%, above or        below the maximum interfacial area when the channel is open to        only one outlet, and    -   wherein the space between the side surface of the valve        distributor and the side surface of the valve chamber, and the        space between the first end of the valve distributor and the        first end of the valve chamber, are small enough that when gas        is fed into said inlet the amount that flows through said spaces        to an outlet that is not open to the channel is less than the        amount of gas that flows through the channel to the outlet or        outlets to which at least a portion of the channel is open.

In a preferred embodiment of this valve, the valve distributor furthercomprises a first spindle that extends axially from said first end intothe first end of said valve chamber, and a second spindle that extendsaxially from said second end into the second end of said valve chamberwithout occupying all of said open space, and wherein said valve bodycontains bearings on which said first and second spindles are rotatableabout said axis.

In a further preferred embodiment of this valve, a passageway isprovided within said valve distributor such that one end of thepassageway opens to said channel and another end of the passageway opensto a point located on the side surface of the valve distributor thatcannot be open to an outlet that is at the same time open to at least aportion of the channel. This passageway may further comprise a flowcontrol that can be adjusted to control the amount of gas that can flowthrough the passageway.

Another aspect of the present invention is burner apparatus comprising

(A) a central feed port having an axis;

(B) first supply apparatus for injecting a first stream comprisingmaterial selected from the group consisting of fuel, oxidant, andmixtures thereof, through the central feed port along the axis of thecentral feed port;

(C) three or more outer ports, each having an axis which converges ordiverges with respect to the axis of the central feed port; and

(D) three or more branched or unbranched supply lines, equal in numberto the number of outer ports, wherein one end of each of said supplylines is connected to a different one of said supply ports and the otherend of each of said supply lines is connected to a controllable supplyapparatus for sequentially injecting material selected from the groupconsisting of fuel, oxidant, inert material, and mixtures thereof, intoand through different ones of said supply lines whereby said material issequentially ejected from different ones of said outer ports as asequence of second streams having a momentum sufficient to deflect thefirst stream from the axis of said central feed port;

-   -   wherein said controllable supply apparatus comprises

(E) a valve that comprises a valve body having a valve chamber thereinhaving opposed first and second ends and a side surface extendingbetween said ends, the valve chamber including a first region thatextends from the first end of the valve chamber and that has an axis,

-   -   a valve distributor within the valve chamber and rotatable        therein in said first region about said axis, the valve        distributor having opposed first and second ends and a side        surface between said ends, that is positioned with its first end        facing the first end of the valve chamber and with its side        surface facing at least a portion of the first region of the        valve chamber,    -   said valve chamber including an open space that is bounded by        the second end of said valve distributor, the second end of the        valve chamber, and the side surface of said valve chamber,    -   the valve body having an inlet extending therethrough from the        outer surface of said valve body to said open space,    -   the valve distributor containing a channel extending inwardly        from the side surface of the valve distributor and extending        from the second end of the valve distributor at least a portion        of the distance toward the first end of the valve distributor,        to receive gas from said open space,    -   the valve body having two or more outlets extending therethrough        from the outer surface of said valve body to points in the first        region of the valve chamber that face the side surface of the        valve distributor or at least a portion of said channel,    -   wherein the outlets are dimensioned and located with respect to        each other so that at any rotational orientation of the valve        distributor the channel is open to one outlet or to more than        one outlet, and so that when the channel is open to more than        one outlet at the same time the sum of the interfacial areas at        said outlets stays within 90%, and preferably 50%, above or        below the maximum interfacial area when the channel is open to        only one outlet, and    -   wherein the space between the side surface of the valve        distributor and the side surface of the valve chamber, and the        space between the first end of the valve distributor and the        first end of the valve chamber, are small enough that when gas        is fed into said inlet the amount that flows through said spaces        to an outlet that is not open to the channel is less than the        amount of gas that flows through the channel to the outlet or        outlets to which at least a portion of the channel is open, and

(F) a controller for turning said valve distributor about its axis sothat said channel is sequentially open to different ones of said outletsso as to sequentially provide said material from said open space throughsaid channel to said outlets.

A preferred embodiment of the burner apparatus of the present inventioncomprises

(A) a central feed port having an axis;

(B) three or more outer ports, each having an axis which converges ordiverges with respect to the axis of the central feed port;

(C) one or more auxiliary feed ports situated closer to the central feedport than any of said outer ports are;

(D) first supply apparatus for injecting a first stream comprisingmaterial selected from the group consisting of fuel, oxidant, andmixtures thereof, through the central feed port along the axis of saidcentral feed port;

(E) auxiliary stream supply apparatus for injecting an auxiliary streamcomprising material selected from the group consisting of fuel, oxidant,and mixtures thereof, through said auxiliary feed portsnon-sequentially; provided that at least one of said first stream andsaid auxiliary stream comprises fuel and at least one of said firststream and said auxiliary stream comprises oxidant, and

(F) three or more branched or unbranched supply lines, equal in numberto the number of outer ports, wherein one end of each of said supplylines is connected to a different one of said supply ports and the otherend of each of said supply lines is connected to a controllable supplyapparatus for sequentially injecting material selected from the groupconsisting of fuel, oxidant, inert material, and mixtures thereof, intoand through different ones of said supply lines whereby said material issequentially ejected from different ones of said outer ports as asequence of second streams having a momentum sufficient to deflect thefirst stream from the axis of said central feed port,

-   -   wherein said controllable supply apparatus comprises

(G) a valve that comprises a valve body having a valve chamber thereinhaving opposed first and second ends and a side surface extendingbetween said ends, the valve chamber including a first region thatextends from the first end of the valve chamber and that has an axis,

-   -   a valve distributor within the valve chamber and rotatable        therein in said first region about said axis, the valve        distributor having opposed first and second ends and a side        surface between said ends, that is positioned with its first end        facing the first end of the valve chamber and with its side        surface facing at least a portion of the first region of the        valve chamber,    -   said valve chamber including an open space that is bounded by        the second end of said valve distributor, the second end of the        valve chamber, and the side surface of said valve chamber,    -   the valve body having an inlet extending therethrough from the        outer surface of said valve body to said open space,    -   the valve distributor containing a channel extending inwardly        from the side surface of the valve distributor and extending        from the second end of the valve distributor at least a portion        of the distance toward the first end of the valve distributor,        to receive gas from said open space,    -   the valve body having two or more outlets extending therethrough        from the outer surface of said valve body to points in the first        region of the valve chamber that face the side surface of the        valve distributor or at least a portion of said channel,    -   wherein the outlets are dimensioned and located with respect to        each other so that at any rotational orientation of the valve        distributor the channel is open to one outlet or to more than        one outlet, and so that when the channel is open to more than        one outlet at the same time the sum of the interfacial areas at        said outlets stays within 90%, preferably 50%, above or below        the maximum interfacial area when the channel is open to only        one outlet, and    -   wherein the space between the side surface of the valve        distributor and the side surface of the valve chamber, and the        space between the first end of the valve distributor and the        first end of the valve chamber, are small enough that when gas        is fed into said inlet the amount that flows through said spaces        to an outlet that is not open to the channel is less than the        amount of gas that flows through the channel to the outlet or        outlets to which at least a portion of the channel is open, and

(H) a controller for turning said valve distributor about its axis sothat said channel is sequentially open to different ones of said outletsso as to sequentially provide said material from said open space throughsaid channel to said outlets.

Another aspect of the present invention is a combustion methodcomprising

(A) injecting a first stream comprising material selected from the groupconsisting of fuel, oxidant, and mixtures thereof, through a centralfeed port that has an axis, along the axis of said central feed port;

(B) providing three or more outer ports each having an axis whichconverges or diverges with respect to the axis of the central feed port;

(C) providing three or more branched or unbranched supply lines, equalin number to the number of outer ports, wherein one end of each of saidsupply lines is connected to a different one of said supply ports andthe other end of each of said supply lines is connected to acontrollable supply apparatus for sequentially injecting materialselected from the group consisting of fuel, oxidant, inert material, andmixtures thereof, into and through different ones of said supply lines,

(D) sequentially injecting said material into different ones of saidsupply lines and thereby sequentially ejecting said material throughdifferent ones of one or more of said outer ports as a sequence ofsecond streams having sufficient momentum to deflect said injected firststream from the axis of said central feed port and to form a mixturewith the deflected first stream, and

(E) combusting the mixture of first and second streams,

-   -   wherein said controllable supply apparatus comprises

(F) a valve that comprises a valve body having a valve chamber thereinhaving opposed first and second ends and a side surface extendingbetween said ends, the valve chamber including a first region thatextends from the first end of the valve chamber and that has an axis,

-   -   a valve distributor within the valve chamber and rotatable        therein in said first region about said axis, the valve        distributor having opposed first and second ends and a side        surface between said ends, that is positioned with its first end        facing the first end of the valve chamber and with its side        surface facing at least a portion of the first region of the        valve chamber,    -   said valve chamber including an open space that is bounded by        the second end of said valve distributor, the second end of the        valve chamber, and the side surface of said valve chamber,    -   the valve body having an inlet extending therethrough from the        outer surface of said valve body to said open space,    -   the valve distributor containing a channel extending inwardly        from the side surface of the valve distributor and extending        from the second end of the valve distributor at least a portion        of the distance toward the first end of the valve distributor,        to receive gas from said open space,    -   the valve body having two or more outlets extending therethrough        from the outer surface of said valve body to points in the first        region of the valve chamber that face the side surface of the        valve distributor or at least a portion of said channel,    -   wherein the outlets are dimensioned and located with respect to        each other so that at any rotational orientation of the valve        distributor the channel is open to one outlet or to more than        one outlet, and so that when the channel is open to more than        one outlet at the same time the sum of the interfacial areas at        said outlets stays within 90%, preferably 50%, above or below        the maximum interfacial area when the channel is open to only        one outlet, and    -   wherein the space between the side surface of the valve        distributor and the side surface of the valve chamber, and the        space between the first end of the valve distributor and the        first end of the valve chamber, are small enough that when gas        is fed into said inlet the amount that flows through said spaces        to an outlet that is not open to the channel is less than the        amount of gas that flows through the channel to the outlet or        outlets to which at least a portion of the channel is open, and

(G) a controller for turning said valve distributor about its axis sothat said channel is sequentially open to different ones of said outletsso as to sequentially provide said material from said open space throughsaid channel to said outlets.

A preferred embodiment of the method of the present invention comprises

(A) injecting a first stream comprising material selected from the groupconsisting of fuel, oxidant, and mixtures thereof, through a centralfeed port that has an axis, along the axis of said central feed port;

(B) providing three or more outer ports each having an axis whichconverges or diverges with respect to the axis of the central feed port;

(C) providing one or more auxiliary feed ports situated closer to thecentral feed port than any of said outer ports are;

(D) injecting an auxiliary stream comprising material selected from thegroup consisting of fuel, oxidant, and mixtures thereof, through saidauxiliary feed ports non-sequentially; provided that at least one ofsaid first stream and said auxiliary stream comprises fuel and at leastone of said first stream and said auxiliary stream comprises oxidant,

(E) providing three or more unbranched supply lines, equal in number tothe number of outer ports, wherein one end of each of said supply linesis connected to a different one of said supply ports and the other endof each of said supply lines is connected to a controllable supplyapparatus for sequentially injecting material selected from the groupconsisting of fuel, oxidant, inert material, and mixtures thereof, intoand through different ones of said supply lines,

(F) sequentially injecting said material into different ones of saidsupply lines and thereby sequentially ejecting said material throughdifferent ones of one or more of said outer ports as a sequence ofsecond streams having sufficient momentum to deflect said injected firststream from the axis of said central feed port and to form a mixturewith the deflected first stream, and

(G) combusting the mixture of first and second streams,

-   -   wherein said controllable supply apparatus comprises

(H) a valve that comprises a valve body having a valve chamber thereinhaving opposed first and second ends and a side surface extendingbetween said ends, the valve chamber including a first region thatextends from the first end of the valve chamber and that has an axis,

-   -   a valve distributor within the valve chamber and rotatable        therein in said first region about said axis, the valve        distributor having opposed first and second ends and a side        surface between said ends, that is positioned with its first end        facing the first end of the valve chamber and with its side        surface facing at least a portion of the first region of the        valve chamber,    -   said valve chamber including an open space that is bounded by        the second end of said valve distributor, the second end of the        valve chamber, and the side surface of said valve chamber,    -   the valve body having an inlet extending therethrough from the        outer surface of said valve body to said open space,    -   the valve distributor containing a channel extending inwardly        from the side surface of the valve distributor and extending        from the second end of the valve distributor at least a portion        of the distance toward the first end of the valve distributor,        to receive gas from said open space,    -   the valve body having two or more outlets extending therethrough        from the outer surface of said valve body to points in the first        region of the valve chamber that face the side surface of the        valve distributor or at least a portion of said channel,    -   wherein the outlets are dimensioned and located with respect to        each other so that at any rotational orientation of the valve        distributor the channel is open to one outlet or to more than        one outlet, and so that when the channel is open to more than        one outlet at the same time the sum of the interfacial areas at        said outlets stays within 90%, preferably 50%, above or below        the maximum interfacial area when the channel is open to only        one outlet, and    -   wherein the space between the side surface of the valve        distributor and the side surface of the valve chamber, and the        space between the first end of the valve distributor and the        first end of the valve chamber, are small enough that when gas        is fed into said inlet the amount that flows through said spaces        to an outlet that is not open to the channel is less than the        amount of gas that flows through the channel to the outlet or        outlets to which at least a portion of the channel is open, and

(I) a controller for turning said valve distributor about its axis sothat said channel is sequentially open to different ones of said outletsso as to sequentially provide said material from said open space throughsaid channel to said outlets.

Preferably, the first stream comprises material selected from the groupconsisting of fuel, oxidant, and mixtures thereof, and the second streamcomprises material selected from the group consisting of fuel, oxidant,inert material, and mixtures thereof.

As used herein, the “axis” of a port is the centerline of the path thatfluid injected out of that port follows in the absence of influence byintersecting fluid flows.

As used herein, material is “inert” if it does not participate in thecombustion of fuel and oxidant, and a stream of material is “inert” ifit does not contain material that participates in the combustion of fueland oxidant.

As used herein, the channel and an outlet are “open” one to the other ifgas can flow in a straight line through any part of the opening of theoutlet into any part of the channel, without encountering solidstructure.

As used herein, the “interfacial area” is the area of the portion (up to100%) of an outlet's opening in the inner side surface of the valvechamber through which gas can flow radially outwardly out of the channelin the valve distributor. For instance, referring to FIGS. 11A and 11B(in which the outer opening of the channel is narrower than the openingof the outlet) and FIG. 11C (in which the outer opening of the channelis wider than the opening of the outlet), the interfacial areas are theareas of the shaded regions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an embodiment of burner apparatus according toone aspect of the present invention.

FIG. 2 is a cross-sectional view of the embodiment of FIG. 1, seen fromabove.

FIG. 3 is a cross-sectional view of the embodiment of FIG. 1, seen fromthe side.

FIG. 4 is a cross-sectional view of the embodiment of FIG. 1, seen fromthe side opposite the side from which FIG. 3 is seen.

FIG. 5 is a front view of another embodiment of burner apparatusaccording to the present invention.

FIG. 6 is a cross-sectional view of the embodiment of FIG. 5, seen fromabove.

FIG. 7 is a perspective view of the exterior of a valve according to thepresent invention.

FIG. 8 is a cross-sectional view of a valve according to the presentinvention.

FIG. 9 is a perspective view of a valve distributor useful in thepresent invention.

FIGS. 10A and 10B are respectively top and side cross-sectional views ofanother embodiment of a valve distributor useful in the presentinvention.

FIGS. 11A, 11B and 11C are plan views of the opening of an outlet seenfrom within a channel.

FIGS. 12A and 12B are plan views of representative arrangements ofopenings of outlets that are adjacent to each other.

DETAILED DESCRIPTION OF THE INVENTION

As indicated, one aspect of the present invention is the combination ofthe valve described herein with a burner that can generate anon-stationary flame.

The burner portion of the present invention is generally referred to as20 in FIGS. 1-4. Burner 20 is preferably formed of refractory materialthat is capable of retaining its shape and composition when exposed tothe temperatures of 1000° F. to 3000° F. to which the burner may beexposed. Examples of such materials include alumina, silica, AZS(alumina-zirconia-silica), mullite, zirconia, and zirconite. Burner 20can be part of a roof, side wall or bottom of an enclosure such as afurnace in which the desired combustion is carried out.

Central feed port 9 and outer ports 1 through 8 open in the front 22 ofburner 20. Central feed port 9 and the outer ports may be, but are notrequired to be, in the same plane, so long as the other characteristicsdescribed herein are observed. Central feed port 9 can comprise oneopening as shown in FIG. 1, or can comprise two or more openings(preferably 1 to 8, more preferably 1 to 3) openings which should belocated close to each other so that material ejected out the openingsmerges in the form of a flow of the ejected material having one axis 39of flow. Examples include multiple single holes, or concentricallyarranged annular openings.

While any number of outer ports greater than 2 outer ports may bepresent, more than about 30 outer ports are usually not necessary. Threeto 20 outer ports are usually satisfactory, and preferably 6 to 12 outerports may be provided. The distance from the central feed port 9 to eachouter port can be the same, but this is not necessary. Instead, eachouter port that is provided can be a different distance from centralfeed port 9, or some outer ports can be one given distance from centralfeed port 9 while another group of outer ports can be a second givendistance from port 9. That is, the outer ports can be arrayed in theform of one circle around port 9, as shown in FIG. 1, or they may bearrayed in the form of two circles of different diameters, or they maybe arrayed in the form of an ellipse, or two ellipses, or a rectangle,or two rectangles, and so forth.

The surface that contains the ports can be planar (flat) or concave orconvex, preferably planar (flat) or concave. For concave and convexcases, the surface on which the ports lie can be spherical, ellipsoidalor a polyhedron shape.

Every outer port has an axis, and the axis of every outer port convergesor diverges with respect to the axis 39 of the central feed port 9. Asused herein, the axis of an outer port “converges” with respect to theaxis of the central feed port if those two axes intersect downstream offront 22, and the axis of an outer port “diverges” with respect to theaxis of the central feed port if those two axes intersect upstream offront 22, that is, inside or behind burner 20. Preferably, the axes ofall outer ports all converge, or the axes of all outer ports alldiverge, with respect to the axis of the central feed port. Morepreferably, the axes of all outer ports all converge with respect to theaxis of the central feed port.

The angle at which the axis of each outer port converges or divergeswith respect to the axis of the central fuel port is typically 5 to 85degrees and preferably 10 to 75 degrees. Outer port axes that convergewith respect to the central fuel port axis can be parallel to eachother, or converge toward each other, or converge toward the same pointon the central feed port axis. The outer port axes do not necessarilyhave to converge toward the same point: for instance, if the intent isto promote a moving flame that moves half way on an elliptical contourand half way on a circular contour, the axes of the outer ports wouldnot converge toward the same point on the central feed port axis.

Referring to FIGS. 2, 3 and 4, central feed port 9 is connected bysupply line 19 through burner 20 to first supply apparatus,schematically represented as 40, which provides and injects the materialforming the first stream into supply line 19 so that it is ejected outthrough central feed port 9. Supply line 19 and central feed port 9 arealigned so that the first stream ejected out of port 9 follows axis 39.Preferably, axis 39 of port 9 is perpendicular to surface 22.

Each outer port is connected by its own corresponding separate supplyline through burner 20 to supply apparatus, schematically represented as50, which provides and injects material into each supply line so thatthe material is ejected as second streams out of the outer ports in themanner described herein.

Each supply line is branched or unbranched and connects supply apparatus50 at one of its ends to its own outer port at its other end. Unbranchedsupply lines are preferred as they provide the advantages of nodiversion of material into branch lines or through valves controllingaccess to branch lines. Using outer ports fed by unbranched supply linesenables more reliable and reproducible control of the flame pattern inthe manner described herein.

In FIGS. 2, 3 and 4, not all passages connecting to outer ports areshown, for ease of reference and disclosure. As shown in FIG. 2, outerports 2 and 3 are fed by supply lines 12 and 13, respectively, and outerports 7 and 8 are fed by supply lines 17 and 18, respectively. Supplyline 1 that feeds outer port 1 is not shown in FIG. 2, so that supplyline 19 can be shown, but supply line 11 is shown in FIGS. 3 and 4. Asshown in FIG. 3, outer ports 1 and 2 are fed by supply lines 11 and 12,respectively, and outer ports 7 and 8 are fed by supply lines 17 and 18,respectively. Supply line 13 feeding outer port 3 is not shown in FIG. 3so that supply line 19 can be shown. As shown in FIG. 4, outer ports 1and 8 are fed by supply lines 11 and 18, respectively, and outer ports 6and 5 are fed by supply lines 16 and 15, respectively. Supply line 17feeding outer port 7 is not shown in FIG. 4 so that supply line 19 canbe shown.

The supply lines feeding to the outer ports can proceed straight throughburner 20, as shown in FIGS. 1-4, but they can instead be constructed toinclude a first portion, ending at the outer port, whose axis is at aconverging or diverging angle with respect to the axis of the centralfeed port, and to include a second portion intersecting with the firstportion within burner 20 wherein the axis of the second portion isparallel to supply line 19 or is at some other angle with respect to theaxis of the first portion.

The supply lines feeding the outer ports are preferably formed bydrilling into the material from which the burner 20 is fabricated.Preferably, the supply lines feeding the outer ports and the supply line19 feeding the central feed port are lined with protective material suchas metal. The supply lines can also be created by casting a refractoryblock with large opening and inserting removable nozzles.

In an alternate embodiment, at the opening of some or all outer ports anozzle or orifice can be provided through which the stream is ejected.In such cases, the axis of the nozzle or orifice is the axis of thatouter port. The nozzles or orifices provided for this use may beadjustable so that the axis of each nozzle or orifice can be movedwithout having to replace or redrill the supply line that feeds to theouter port.

The material ejected as the first stream and the material ejected as thesecond stream must, after they have been mixed together, be capable ofcombusting in the presence of an external or embodied source of ignitionor in a combustion chamber at temperatures higher than the self ignitiontemperature of fuel present in the mixture.

In one embodiment, the material ejected as the first stream and thematerial ejected as the second stream both comprise material whichparticipates in combustion of the mixture that is formed of the firstand second streams. For instance, the first stream can comprise fuel, inwhich case the second stream comprises oxidant or a premixed mixture offuel and oxidant. Instead, the first stream can comprise oxidant, inwhich case the second stream comprises fuel or a premixed mixture offuel and oxidant. In another alternative, both of the first stream andthe second stream comprise premixed mixtures of fuel and oxidant.Preferably, the first stream comprises fuel and the second streamcomprises oxidant.

In another embodiment, the material ejected as the first streamcomprises fuel or a mixture of fuel and oxidant, and the second streamis “inert”, that is, it does not contain material which participates incombustion of the mixture that is formed of the first and secondstreams. Examples of such material that could be ejected as the secondstream include nitrogen, argon, carbon dioxide, water (liquid or,preferably, vapor), helium, and mixtures thereof.

Suitable fuels include combustible hydrocarbons whether gaseous, liquid,or particulate solid in form. Suitable gaseous fuels include naturalgas, vaporized LPG (liquefied petroleum gas), propane, butane, andgaseous mixtures that contain carbon monoxide, hydrogen, or both carbonmonoxide and hydrogen, such as coke oven gas, blast furnace gas,electric arc furnace gas, and coal gas. Suitable liquid fuels includefuel oil and diesel oil. Liquid fuel should be atomized as it emergesfrom its port (whether the central feed port or outer ports). Suitablesolid fuels include coal of any rank or mixtures of rank, and petroleumcoke. When the fuel is solid, it should have been reduced in particlesize so that it is capable of being fed out of the port with a suitablecarrier gas such as transport air, as is used when feeding pulverizedcoal to the combustion chamber of a coal-fired electricity generatingpower plant.

The oxidant should be a stream that contains 5 vol. % to 100 vol. %oxygen, and preferably 10 vol. % to 100 vol. % oxygen. Air is apreferred oxidant, as is oxygen-enriched air by which is meant air towhich oxygen has been added to raise the oxygen content above that ofair to e.g. at least 20 vol. % or 25 vol. % or even at least 50 vol. %.Another preferred oxidant is a gaseous stream containing at least 80vol. % oxygen or even at least 95 vol. % or even at least 98 vol. %oxygen. Oxidant having this higher oxygen content can be provided fromstorage tanks that contain compressed oxygen gas, from storage tanksthat contain liquid oxygen and provide the oxygen by vaporization ofsuitable amounts of the liquid oxygen, or from on-site air separationunits that produce high-purity oxygen from air, or from an oxygenpipeline. Other gaseous components (such as the aforementioned materialsthat do not participate in combustion) can likewise be provided fromstorage tanks, supply trucks, or pipelines

The supply apparatus 40 that injects into supply line 19 the materialthat is ejected from port 9 as the first stream, and the supplyapparatus 50 that injects into the supply lines the material that isejected from the outer ports as the second streams, include a suitablesource of fuel, or oxidant, or premixed fuel and oxidant, ornon-combusting material, as the case may be, as well as suitableapparatus for propelling the material to and through its port(s).Suitable devices for gaseous material include fans and blowers. Suitabledevices for liquids and particulate solids include atomizers and blowershaving the ability to perform the necessary function of delivering thematerial to and through the port(s) with the desired velocity. Theadditional capabilities of supply apparatus 50 are described below.

The velocity of the first stream ejected by the central feed port shouldtypically be 5 to 1600 feet per second, and preferably 10 to 900 feetper second. The velocity of the second stream ejected by each outerports should typically be 5 to 2000 feet per second and preferably 10 to900 feet per second.

The temperature of the mixture of the first and second streams shouldtypically be up to 3000° F., and preferably up to 2000° F.

In accordance with the present invention, in sequence (1) a secondstream is ejected from one outer port, or from a group of adjacentlylocated outer ports, with sufficient momentum to deflect the ejectedfirst stream from the axis along which it would otherwise be travelingin the absence of that deflection, while at that same point in timematerial is either not being ejected from other outer ports, or is beingejected from other outer ports but not with enough momentum to deflectthe first stream from its axis, and then (2) a second stream is ejectedfrom a different outer port, or from a different group of adjacentlylocated outer ports, with sufficient momentum to deflect the firststream (in a direction different from the direction it was previouslydeflected) from the axis along which it would otherwise be traveling inthe absence of that deflection, while at that same point in timematerial is either not being ejected from other outer ports, or is beingejected from other outer ports but not with enough momentum to deflectthe first stream from its axis, following which the ejection of secondstreams continues from a periodically changing outer port or group ofouter ports. It should be noted that the flow of second streams ofmaterial that deflect the flow from the central feed port canoccasionally be reduced, or interrupted, so that the ejected firststream of material flows along the axis of the central feed porttemporarily, following which a second stream is again ejected from anouter port or group of outer ports to again deflect the first stream.

To carry out this function, supply apparatus 50 that injects materialinto the supply lines for ejection from the respective outer ports asthe second streams includes mechanism for sequentially varying thesupply line or lines into which the material is injected, with a highenough velocity, to sequentially vary the outer port or ports throughwhich the second stream is ejected at any point in time with a momentumhigh enough to deflect the first stream being ejected from the centralfeed port from its axis.

The preferred mode of sequentially controlling the flow of materialcomprising the second stream through the outer ports employs asingle-valve mechanism, situated between the individual supply lines andan upstream common source of supply of the second stream material, thatincludes a movable piece such as a rotatable diverter. The movable piececontains a principal opening through which the second stream materialcan flow into an outer port supply line with which the principal openingis aligned at any particular point in time. The movable piece otherwiseblocks flow to the other outer port supply lines, or optionally alsoincludes additional openings which are aligned with one or more of theother outer port supply lines when the principal opening is aligned withone of the outer port supply lines. The movable piece and the outer portsupply lines are positioned with respect to each other so that themovable piece can be moved (for instance, rotated around its own axis)so as to bring outer port supply lines into alignment with the principalopening in a sequence that enables the material comprising the secondstream to flow to a sequence of outer ports. When the materialcomprising the second stream is applied under pressure upstream of themovable piece, rotation of the movable piece aligns the principalopening with a sequence of outer port supply lines while permitting thesecond stream to flow into no other outer port supply lines, or inlesser quantities into other outer port supply lines, depending onwhether any of the aforesaid additional openings are provided.

Preferred embodiments of this mechanism are described herein, withreference to FIGS. 7, 8, 9, 10A, 10B, 11A, 11B and 11C.

Referring to FIG. 7, valve 50 includes valve body 48 which has an outersurface 51 through which pass inlet 55; outlets 56, and optional butpreferred seal leakage vents 57. Bottom plate 58, top bearing seal 62and first spindle 60 are also shown. The first spindle 60 can includeflat region 87 to facilitate attaching apparatus (a motor, or gearswhich are attached to a motor) which controllably rotates the spindleand the valve distributor 82. The valve body 48 is preferably made ofmetal such as steel or brass.

FIG. 8 shows the interior of the valve, including inlet 55, two outlets56, bottom plate 58, top bearing seal 62, and first spindle 60, whichappear in FIG. 7. Valve body 48 houses valve chamber 49 which has firstend 52, second end 53, and wall surface 54. Surface 54 is shown as beingcylindrical for at least the portion of the chamber 49 within whichvalve distributor 82 rotates. However, this portion of surface 54 caninstead have a different shape, such as conical (converging upwardlytoward a point or diverging upwardly), or other shape within which thevalve distributor can rotate. Also shown in FIG. 8 are second spindle61, one countersunk screw 64 of several that would hold bottom plate 58to valve body 48, access plug 66 for accessing and replacing bottombearing 70, access plug o-ring seal 67 and its groove 68, bottom bearing70, bottom plate o-ring seal 71 and its groove 72, top o-ring seal 73and its groove 74, seal leakage deflection collar 76, seal leakageexpansion chamber 78 (which connects by ducts, not shown, to vents 57);top bearings 79 (preferably an angular contact rolling element pair forthrust and radial loads), and bearing retaining clip 80. Valvedistributor 82 has first end 83, second end 84, and outer surface 85.Space 86, not fully occupied by valve distributor 82, is within valvechamber 49 in the region into which inlet 55 feeds gas. Second spindle61 is optional but preferred, to provide stability for the rotatingvalve distributor.

FIG. 9 shows valve distributor 82, first spindle 60, second spindle 61,and first end 83, flat region 87, groove 88 for retaining clip 80, andseal leakage deflection collar 76. Valve distributor 82 is shown asbeing cylindrical in shape but it can instead have another shape such asconical (converging upwardly toward a point or diverging upwardly) whichcorresponds closely to the space closer to the first end 52 of valvechamber 49. Also shown is channel 90, which is open at outer surface 85of valve distributor 82 and extends inwardly into valve distributor 82.Channel 90 is open at second end 84 and extends upwardly from second end84 at least partway toward first end 83, far enough so that it can beopen to the outlets 56 as valve distributor 82 rotates. Channel 90 isshown as extending upwardly from end 84 in a direction parallel to theaxis of rotation. Channel 90 can instead have a different path, such ashelical, along surface 85.

Valve distributor 82 fits closely within valve chamber 49 but space canbe provided between the side wall surfaces 85 and 54 of valvedistributor 82 and valve chamber 49, and between the first ends 83 and52 of valve distributor 82 and valve chamber 49, so that a minor amountof gas can flow from space 86 through that space to reach every outlet,even outlets that are not at the moment open to the channel 90.Providing some gas to each outlet at all times is preferred as itprovides some cooling to the openings at the front of the burner.

As indicated above, the space between the side surface 85 of valvedistributor 82 and the side surface 54 of valve chamber 49, and thespace between the first end 83 of valve distributor 82 and the first end52 of valve chamber 49, are small enough that when gas is fed into saidinlet the amount that flows through said spaces to an outlet that is notopen to the channel 90 is less than the amount of gas that flows throughthe channel 90 to the outlet or outlets to which at least a portion ofthe channel 90 is open. Preferably, the spaces are small enough thateven less gas can pass therethrough, that is, the amount that flowsthrough said spaces to an outlet that is not open to the channel 90 isnot more than 25%, more preferably not more than 10%, and even morepreferably not more than 5%, of the amount of gas that flows through thechannel 90 to the outlet or outlets to which at least a portion of thechannel 90 is open.

FIGS. 10A and 10B illustrate another, optional, manner in which gas canbe provided to outlets. Passageway 92 is provided through valvedistributor 82, from an opening 91 in channel 90 (whether in the bottomof channel 90, as shown in FIG. 10A, or in one of the walls of channel90, as shown in FIG. 10B) to an opening 93 in the side surface of valvedistributor 82. In a preferred version of this embodiment, adjustablescrew 94 is provided whose tip extends to or into passageway 92. Byturning the screw to adjust how much of the tip extends into passageway92, or to move the tip out of passageway 92, one can vary the amount ofgas that flows through and out of passageway 92. In the embodiment ofthe valve illustrated in FIGS. 7 and 8, the adjustment screw 94 could beaccessed by removing bottom plate 58.

The outlets 56 can be arrayed in any of a number of ways around thevalve body 48, but certain arrangements are preferred. The outlets arepreferably placed on two or more levels, to allow closer packing of theoutlets so that a smaller valve may be used (for ease of manufacture,handling and economy). The limit of the port packing tightness is basedon at least two constraints. The first is in good practice for theattachment of conduits to the outlet conduits, so that the fastening ofany one of the outlet conduits will not interfere with the fastening ofthe other outlet conduits. This applies to threaded connections whereeither the high points of the hose end connecting adapter wouldinterfere or where turning of the wrench itself would be overlyobstructed. It also applies in cases where other means of attachment areused such as welding or quick-disconnects. Another consideration in thetightness of the packing of the outlets is in the allowable stresses ofthe material remaining between the ports given the internal pressure,any bending moments induced by the weight of attached hoses, and inducedstress from the method of attachment whether it be threaded, welded,flanged or quick disconnects.

Another preferred mode is that the outlets are sized identically anddistributed evenly. It should be noted that while relatively constantflow through the various outlets may be desired in some applications ofthis invention, it is not required in others. Thus, the descriptionsherein of how to make a valve according to this invention need not belimited to embodiments that provide such relatively constant flows.

In addition, a preferred distribution of the outlet ports is such that asingle line drawn vertically tangent with the interior edge of one ofthe outlets either does not intersect the adjacent outlet, or is atangent line for the interior edge of the adjacent outlet. Thisrelationship is illustrated in FIG. 12A. For instance, for a six portvalve in this mode of arranging the outlets, there are six evenlyspaced, imaginary, vertical lines each of which is simultaneouslytangent to two adjacent outlets. At the same time, channel 90 is sizedso that at the surface 85 of valve distributor 82 it is the same nominalwidth as the diameters of the outlets at the wall surface 54. Thisarrangement enables maintaining a constant primary outlet flow area nomatter the position of channel 90. That is, as valve distributor 82rotates and the interfacial area with one outlet decreases, the edge ofthe adjacent outlet port begins to be open and the interfacial area withthat next outlet increases by a corresponding amount so that the sametotal outlet area is exposed to the flowing gas.

The outlets can instead be spaced more closely, so that a vertical lineon surface 54 can pass through two or more outlets. However, it is stillpreferred that even if the outlets are spaced so that a vertical linethat is tangent to one outlet opening can pass through the opening ofthe closest adjacent outlet, the outlets should still be spaced apartfrom one another enough so that a vertical diameter of one outlet'sopening does not intersect the opening of any of the closest adjacentoutlets. This relationship is illustrated in FIG. 12B.

The spacing of the outlets achieves the aforementioned preference thatat any rotational orientation of the valve distributor the channel isopen to one outlet or to more than one outlet, and that when the channelis open to more than one outlet at the same time the sum of theinterfacial areas at said outlets stays within 90% above or below themaximum interfacial area when the channel is open to only one outlet.Preferably, the sum of the interfacial areas at said outlets stayswithin 50% or 25%, more preferably within 10%, and even more preferablywithin 5%, above or below the maximum interfacial area when the channelis open to only one outlet.

Sizing of the valve is based upon the amount of flow required throughthe connections and the number of connections needed. Generally theconnections are sized to keep the pressure drop reasonable andeconomical and this is done with a flow velocity less than sonicvelocity and generally between 10 and 300 ft/s. The size of the valvebody is then based upon the diameter and height required to distributethe number and size of connections around the periphery whilemaintaining a suitably sturdy device (by not allowing the distancebetween openings to be so narrow that the material cannot carry theloads required) and considering that the valve distributor must be ableto transition from outlet to outlet without significantly altering theflow. The channel 90 itself is sized to maintain the velocity less thansonic velocity and generally between 10 and 600 ft/s for a reasonableand economical pressure drop. Materials of construction are selectedbased on whether materials will be in contact with the process fluid.

In operation, gas (preferably, the oxidant rather than fuel, though itcan ge gaseous fuel) is fed into inlet 55 from a source (not shown) suchas a pump or a tank in which the gas is stored under pressure. Thesource should have controls such as an adjustable valve that enables theflow of gas to be shut off, turned on, and varied in flow rate. The gasenters into space 86 and passes into channel 90 and then to variousoutlets 56 as the valve distributor 82 rotates under the action of amotor that can be controlled so that the operator can vary or set therate at which the valve distributor is rotated, and preferably thelength of time that the valve distributor rests in each position ittakes that aligns channel 90 with one or more outlets. The controllerpreferably also controls the sequence of outlets at which the channel 90is aligned.

The valve described herein can be electronically or pneumaticallycontrolled. With electronic control, a variable frequency driver woulddrive an electric motor which turns the rotary valve, and the rotationalspeed would be controlled by a PLC. Alternatively, the valve can berotated by a stepper motor that is executing a program stored in a motorcontrol unit. To control a pneumatically operated rotary valve, thesupply pressure of the compressed driving fluid would be varied andcontrolled.

Using either of these control schemes or any other control scheme thatachieves the same function, the second stream is provided in sequencethrough an outer port or to a group of adjacent outer ports at amomentum sufficient to deflect the first stream from its axis. Thesequential feeding of second streams having that momentum sequentiallychanges the outer port or outer ports which is or are ejecting thesecond streams that deflects the first stream, which in turnsequentially changes the direction in which the first stream isdeflected. The sequence of first stream-deflecting flows of secondstreams preferably proceeds around and around the array of outer ports,from one outer port and then from its nearest neighbor and then fromthat outer port's nearest neighbor and so forth, such as out of outerports 1 through 8 in the numerical sequence in which they are numberedin FIG. 1, with flow out of outer port 8 being followed by flow out ofouter port 1, and so on. Alternatively, the sequence of outer ports fromwhich first stream-deflecting flows of second streams are ejected canskip from one outer port to another non-adjacent outer port, then toanother that is adjacent or non-adjacent, and so forth. Furthermore, thesequence can be repetitive, or it can be randomized so that there is noregularity to which outer port will be the next to eject a second streamto deflect the flow of the first stream. The sequence, whether regularor randomized, can be programmed into and carried out by the PLC.

Typically, the direction of flow of the first stream-deflecting flow ofthe second stream changes often enough that a complete sequence ofdirection changes occurs in 0.03 to 30 minutes, preferably 0.1 to 10minutes.

While the present invention can be carried out by ejecting firststream-deflecting flows of material as the second stream from one outerport at a time, it is also possible and often is preferred to eject thesecond streams from a pair of adjacent outer ports at a time, or from agroup of three outer ports comprising a middle port and an adjacent porton each side of the middle port. That is, referring to FIG. 1, thesecond stream that deflects the first stream can come from any one ofouter ports 1 through 8, or from two adjacent ports at a time such asfrom ports 1 and 2, then from ports 2 and 3, then from ports 3 and 4,and so forth. Alternatively, the flows can come from ports 1, 2 and 3,then from ports 2, 3 and 4, then from ports 3, 4 and 5, and so forth.Indeed, the number of outer ports from which a second stream is directedto deflect the first stream can be from only 1 up to 1 less than thetotal number of outer ports, and preferably from 1 to 4 outer ports.

The ratio of the momentum of the stream ejected by the outer port orouter ports which deflect the first stream, to the momentum of the firststream from the central feed port, is typically 1.01 to 20 andpreferably 1.1 to 10.

The exit openings of the ports can vary in shape (geometry) and area aslong as the streams are ejected within an effective velocity range(which for the first stream ejected from the central feed port is avelocity typically between 5 to 1600 feet per second, and preferably 10to 900 feet per second; and for the second stream ejected by outer portsis a velocity between 5 to 2000 feet per second, and preferably 10 to900 feet per second).

The distance between the outer port to the center port can vary fromouter port to outer port. Preferably, the outer ports should lie on acircular or elliptical pattern.

Of the total amount of material ejected as second stream through allouter ports at any point in time, typically 10 to 100% and preferably 50to 100% of that amount should be ejected by the outer port or ports thatare providing the momentum to deflect the first stream.

When the axes of the outer ports converge with respect to the axis ofthe central feed port, the first stream-deflecting second stream orstreams deflects the first stream from its axis by “pushing” it from itsaxis. When the axes of the outer ports diverge with respect to the axisof the central feed port, the first stream-deflecting second stream orstreams deflects the first stream from its axis by drawing or aspiratingthe first stream toward the second stream(s). In either situation, thesecond stream or streams intersects with and mixes with the firststream.

Once ignited, the mixture that forms of the first and second streamscombusts and forms a flame. The direction in which the first stream isdeflected (by the second stream or streams) becomes the direction inwhich the mixture of the first and second streams extends which in turnis the direction that the flame extends. Thus, the orientation of theflame with respect to the axis of the central feed port changes witheach intersection between the first stream and a first stream-deflectingsecond stream coming from a different outer port or group of outerports. For example, carrying out the present invention with a burnerlike that shown in FIGS. 1-4, and ejecting the second stream from theouter ports in the numerical sequence of ports 1 through 8 in thatorder, then as one looks at the front of the burner in the view providedin FIG. 1 the flame would be deflected so that the flame would obscureport 5, then port 6, then port 7, then port 8 (at which point the firststream-deflecting flow of second stream would be from port 4) and soforth as the flame would continue to appear to sweep out a cone whosevertex would be at port 9.

This behavior continually provides the desired heat of combustion to thematerial being heated and to the enclosure in which the combustion isoccurring, but does so in a way that provides a more uniform temperaturedistribution because the continually shifting orientation of the flameavoids the creation of “hot spots” or regions which become overheatedbecause of the uninterrupted proximity to the hottest regions of theflame. This in turn permits combustion conditions that provide a hotteraverage flame temperature, since there is less need to be constrained byavoidance of “hot spots”.

The ratio (or proportion) of material in the first and second streamsneeds to be appropriate to maintaining combustion of the mixture thatforms upon intersection and mixing of the first and second streams.Thus, for each mixture of fuel and oxidant that forms as the flamechanges orientation by ejection of second stream from each sequentiallydiffering outer port, taking into account oxidant entering the flamefrom the surroundings plus any oxidant fed through any auxiliary feedport(s) plus oxidant fed in the first and second streams, the ratio ofthe total amount of oxygen fed to the amount of fuel fed must be from0.5 to 10 times the stoichiometric ratio, where the stoichiometric ratiois defined as the mole amount of oxygen per mole of fuel that isrequired to completely combust the fuel to CO₂ and H₂O. For instance,the stoichiometric ratio defined in this way for combustion of methaneis 2, so the ratio of oxygen to methane to establish in each mixture offirst and second combustant that is formed is 2×(0.5 to 10) or 1 to 20.

The distance between the axis of the central feed port and the nearestouter port is typically 3 to 24 inches and preferably 6 to 18 inches.

In addition to providing the advantage of a more uniform temperatureprofile of the surface of the material to be heated, or heated andmelted, and for the resulting heating that the flame provides, thepresent invention is advantageous in that it can be carried out usingstaged combustion techniques that help reduce production of nitrogenoxides. Staging can be effected by permitting the injection of smallamounts of material through the outer ports that are not involved at agiven point of time in deflecting the first stream.

A preferred alternative embodiment, illustrated in FIGS. 5 and 6,includes one or more auxiliary feed ports through which a stream isejected to help stabilize the flame and control formation of nitrogenoxides. A preferred auxiliary feed port is an annular orifice 60 aroundthe central feed port 9. Instead, the annular orifice 60 can be replacedby a series of distinct openings arrayed around the central feed port 9.The one or more auxiliary feed ports are closer to the central feed portthan any of the outer ports are. The auxiliary feed port or ports arefed through auxiliary supply line 58 from auxiliary feed source 56. Inthis embodiment, the stream ejected by the central feed port 9 comprisesfuel, oxidant, or a mixture of fuel and oxidant, and the auxiliary feedport or ports 60 eject fuel, oxidant, or a mixture of fuel and oxidant,provided that at least one of the central feed port and the auxiliaryfeed port(s) ejects fuel and at least one of the central feed port andthe auxiliary port(s) ejects oxidant. The material fed to the centralfeed port and the material fed to the auxiliary port(s) by theirrespective sources of supply 40 and 56 are provided and injected bymeans of apparatus known in this technical field.

The material fed to auxiliary feed port or ports 60 is fednon-sequentially, that is, the rate at which material is fed to andthrough the auxiliary feed port(s) does not vary during operation, anddoes not fluctuate between different rates during operation.

The invention provides many other advantages. One is that the presentinvention provides a flame with wide coverage to transfer heat moreefficiently to the material being heated. Also, flame direction can bechanged easily, even during operation of the burner, without requiringany change to the hardware (burner and/or flow control valves), simplyby changing the directions to the controller that governs the sequentialfeeding through the outer ports.

Another advantage is the ability to point the flame in a pre-determineddirection for a pre-determined period of time. That is, the flame doesnot need to be moving constantly. The frequency of the changes of flameorientation, and the period of time the flame points in any givendirection can be set, for instance, at the moment the furnace is chargedand according to the way the furnace has been charged (for instance, theflame can stay pointed to a given direction where there is a greateramount of charged material to be heated, or where there is more freshlycharged material that is initially at a lower temperature.

Additional benefits of the invention include:

Fewer “hot spots” are formed in the refractory wall, which can increasethe furnace life.

Promoting more uniform heat transfer pattern means fewer “cold spots”,which can lead to increased melt rate or heat rate.

Fewer burners are required due to the uniform heat transfer pattern,thus affording equivalent production for a lower investment.

A burner installed in the roof leaves more locations in the side wall toinstall peep holes, service doors, and charging doors.

A burner with moving flame installed in the roof allows the design ofthe combustion system to be optimized for the furnace geometry.

The direction of the flame and the intensity of the flame are determinedby independent jets, i.e., do not rely on nozzle design, gas mixing,fluid flow pattern, and material reliability against degradation factorssuch as chemical attack or spalling, and is less sensitive to variationsin operating parameters that would affect flame stability. The flamestability and characteristics are determined by fixed and robust gasinjection ports. The greater uniformity of temperature avoids localizedhigh temperature regions or spots since the heat is transferred evenlyaround the burner (or melting or heating surface) and not only on onestripe across the charge. The heat is evenly and gently distributed overthe charge. This also permits a potentially lower oxidation rate whenheating materials susceptible to oxidation due to localized hightemperature and high oxygen partial pressure, such as aluminum andsteel.

Other advantages include high flame stability and reduced downtime,because in the unlikely event of clogging of an outer port, the sequenceof injection can be revised to avoid using that port until suitablerepairs can be made.

The invention also provides economic advantages including lowfabrication cost, yield improvement in applications where oxidation is aconcern, such as aluminum melting and steel reheating, and low specificfuel consumption.

1. A valve useful for feeding gas to one or more than one outlets at atotal flow rate that is controlled independently of the number of suchoutlets, comprising a valve body having a valve chamber therein havingopposed first and second ends and a side surface extending between saidends, the valve chamber including a first region that extends from thefirst end of the valve chamber and that has an axis, a valve distributorwithin the valve chamber and rotatable therein in said first regionabout said axis, the valve distributor having opposed first and secondends and a side surface between said ends, that is positioned with itsfirst end facing the first end of the valve chamber and with its sidesurface facing at least a portion of the first region of the valvechamber, said valve chamber including an open space that is bounded bythe second end of said valve distributor, the second end of the valvechamber, and the side surface of said valve chamber, the valve bodyhaving an inlet extending therethrough from the outer surface of saidvalve body to said open space, the valve distributor containing achannel extending inwardly from the side surface of the valvedistributor and extending from the second end of the valve distributorat least a portion of the distance toward the first end of the valvedistributor, to receive gas from said open space, the valve body havingtwo or more outlets extending therethrough from the outer surface ofsaid valve body to points in the first region of the valve chamber thatface the side surface of the valve distributor or at least a portion ofsaid channel, wherein the outlets are dimensioned and located withrespect to each other so that at any rotational orientation of the valvedistributor the channel is open to one outlet or to more than oneoutlet, and so that when the channel is open to more than one outlet atthe same time the sum of the interfacial areas at said outlets stayswithin 90% above or below the maximum interfacial area when the channelis open to only one outlet, and wherein the space between the sidesurface of the valve distributor and the side surface of the valvechamber, and the space between the first end of the valve distributorand the first end of the valve chamber, are small enough that when gasis fed into said inlet the amount that flows through said spaces to anoutlet that is not open to the channel is less than the amount of gasthat flows through the channel to the outlet or outlets to which atleast a portion of the channel is open.
 2. A valve according to claim 1further comprising within said valve distributor a passageway one end ofwhich opens to said channel and another end of which opens to a pointlocated on the side surface of the valve distributor that cannot be opento an outlet that is at the same time open to at least a portion of thechannel.
 3. A valve according to claim 2 further comprising a flowcontrol that can be adjusted to control the amount of gas that can flowthrough said passageway.
 4. A valve according to claim 1 wherein thefirst region of said valve chamber and the valve body rotatable thereinare cylindrical.
 5. A valve according to claim 1 wherein the firstregion of said valve chamber and the valve body rotatable therein areconical.
 6. A valve according to claim 1 wherein said channel extendsfrom the second end of said valve distributor toward the first end ofthe valve distributor in a direction parallel to said axis.
 7. A valveaccording to claim 1 wherein the outlets are dimensioned and locatedwith respect to each other so that when the channel is open to more thanone outlet at the same time the sum of the interfacial areas at saidoutlets stays within 50% above or below the maximum interfacial areawhen the channel is open to only one outlet.